Unified Modelling Platform for Building and Systems Energy Efficiency – PLUMES

Interoperability and models capitaIization are the main keywords of the project. The objective of the project is to provide the foundations for enhanced interoperability along two axes: architectural modeling and physical behaviour modeling. Architecural modeling will be ensured through the BIM / Industry Foundation Classes (standard format for building digital modeling), which specifications and related tools are now well-established. In the project, the research focus is therefore mainly on behavioural modeling and the main objective is to develop a software component standard specification to ensure models interoperability. This standard will describe the interfaces that shall be realized and provided by each and every conformant modeling component and, will enable - thanks to the development of an adequate support - to reuse and assemble components. This standard is called MUSE (building energy system unified model). The aim of the project will be to implement a software platform using this standard as a lynchpin, to facilitate its uptake: MUSE components generation tools, components assemblies edition and generation tools, translation tools, methodological framework and support tools for MUSE component development. Then, as an application, the project will provide and make available a first library of MUSE components through a dedicated web platform also delivered in the scope of the project.

• MUSE modelling software component specification: full-fledged specifications of an interoperable, business-agnostic, multi-physical software component with a standard API
• Support tools for edition, development, generation and assembly of MUSE components.
• Software modules for connecting MUSE components and IFC building digital models.
• A first library of MUSE components.
• software modules enabling for MUSE components execution in various target environments.
• A web platform for models sharing and capitalization.

Short term : emergence of a multi-business modelers community in the building domain; generalization of models sharing and reuse.
Medium / long term: Emergence, on the basis of the project results, of a building energy modeling components market.

• Development of a software tool for generation of MUSE components from Modelica models. See: F. Verdière, A. Rezgui, S. Gaaloul, B. Delinchant, L. Gerbaud, F. Wurtz and X. Brunotte, «Modelica models translation into Java components for optimization and DAE solving using automatic differentiation«, IEEE UKSim2012, 14th International Conference on Computer Modelling and Simulation, 28 - 30 March 2012, Cambridge, UK. pp.340-344.
• An in-depth analysis of the IFC with respect to energy systems modeling and some propositions for extending the IFC. See : S. Robert, B. Hilaire, P. Sette, S. Soubra, Paving the way for exhaustive and seamless BIM-based building energy simulation, CIB 2012.
• Definition of the MUSE specification and related application. See: B.Delinchant, F. Wurtz, S. Ploix, X. Brunotte, MUSE: towards a standard for interoperability of multi-purpose building models, Building Simulation 2013.

It is now acknowledged that the general trend of ever-growing energy consumption shall be put to an end and that this raises new and exciting technological challenges. This is especially true for Building energy efficiency since energy consumption of the area represents more than 40% of total consumption (in France and Europe). Improving building efficiency imposes not only to improve building envelopes, but also to provide efficient and reliable working support to practitioners as far as modeling and simulation are concerned (it is a necessary step in order to efficiently take into account energy aspects in building life cycle). A large number of software tools is already available for all modeling and simulation tasks and these already perform quite well. It is however still important to seek to improve them, and not only to obtain more precise and reliable results, but also to make them more interoperable and to improve their connection to other software tools of building life cycle. These two aspects are actually crucial if we want these tools to spread among building design practitioners and doing so, to reach a higher level in building energy efficiency. To this end, the PLUMES project proposes to provide a unified modeling approach, independent from any modeling platform or modeling format or targeted domain. This approach will be completed by a software platform easy to couple with other building lifecycle software tools (and most important, to CAD tools) and which will rely on available modeling / simulation tools.

The project is clearly in line with the theme 1.4 ("modeling and design-support tools") of thematic axis 1 ("Systems-oriented approaches") of ANR Habisol 2010 call. Indeed the call explicitly puts an emphasis on the interoperability issue: "it will be necessary to ensure interoperability (standard data formats) between specific tools of different domains in order to propose completely integrated solutions".

From the scientific and technical points of view, interoperability and ability to reuse models are the main focuses of the projects. The main objective will be to design a candidate standard of components for building and building systems modeling. This standard component will be interoperable, will address various kinds of physics, and will be able to execute in various environment. This standard, which we call MUSE (for Modèle Unifiée pour les Systèmes Energétiques, which may be translated to "unified model for energy systems"), will offer the following features:
- Interoperability: Interoperability of MUSE components will be ensured thanks to a neutral language (i.e. independent from any specifics), from which executable components will be generated;
- Multi-physics: MUSE components will enable dealing with all kinds of physics related to building domain. In particular, thermal, electrical, and control-command domains will be targeted. It will also be possible to model building users, as well as financial aspects (e.g. investment costs). It will be possible as well to extend components to other physics, which are not dealt with in the scope of the project (e.g. lighting);
- Multi-domains: A MUSE component will integrate several models enabling to target various domains: simulation, control, diagnosis, etc.

Therefore, the aim of PLUMES will be to use this MUSE component model as a basis to build a unified software platform for building and building systems modeling. This platform will provide a comprehensive support for MUSE components: components editors and generators, and software modules to execute them in various environments (TRNSYS, MODELICA and G-Home Tech are especially targeted). Software support to connect building information model (expressed in IFC format) and MUSE components will also be provided. At last, a first library of MUSE components will be developed in the scope of the project in order to validate relevance and applicability of the approach.